In recent years, ReRAM (Resistive RAM) having a variable resistance element as memory, has been proposed. Moreover, ReRAM has a structure where the variable resistance element is provided between a sidewall of a word line extending parallel to a substrate and a sidewall of a bit line extending perpendicularly to the substrate, because it enables an even higher degree of integration of a memory cell array to be achieved. However, in a memory cell array of such a structure, an embedding defect of an interlayer insulating film may cause a pattern defect, and so on, and it leads to lowering of reliability of the semiconductor memory device.